Help, Advice, Owners' Discussion and DIY Tutorials on Volvo XC90s. The XC90 proved to be very popular, and very good for Volvo's sales numbers, since its introduction in model year 2003 (North America).

# 1 the outlet the coolant hose attaches to looks to be ribbed . Are these ribs in good condition ? If not replace it . Now I keep spring type hose clamps in stock for most all size heater , radiator hoses . I prefer them over anything else . These maintain CONSTANT tension . I've seen water outlet , t-stat housings and just about anything plastic carrying hot coolant fail over time . Do not be afraid to be liberal and replace anything you think is necessary .
Good luck !

I'll have to have a look at this, as I've never considered changing style from OEM. Constant tension makes sense, though.

As for the ribs, I'll have a good look at the unit when I remove it and let the forum know what I find.

LOL. Many years back when I first saw a 3.2 I6 at a pre-launch training event, A co-worker reached over and released the plastic air bleed line connector on that front and center metal cylinder head fitting. I was the unlucky one standing front and center of the just driven vehicle and it spit a good bit of warm coolant all over my shirt. Seeing that hose in your link made me laugh. I'm calling that SOB tomorrow and giving him some crap.

ouch, hopefully the coolant wasn't fully warmed
I've seen something similar at a junk yard. Random guy asked my to help him undo an intake on a Subaru. Quite complex work, plus there was this gas hose in the way and no apparent gas pressure release valve on that engine. Guy was thinking, since the car been sitting for several weeks (was already missing parts), just cut the gas hose and lift the intake. I warned him to no avail. I was wrenching a bolt on one side of the engine when all of a sudden I hear a pshhhht and the guy jumps back: got sprayed with gasoline directly into one eye - I urged him to run and wash his eye with water for several minutes. Hope he's fine by now

I'm with xheart . The clamp looks too low on the hose and it promoted the hose to come off . The pics of the 3 types of clamps shown in the pics above , I prefer the spring ( constant tension ) type clamp for coolant hoses . I would install a new hose / clamp and use the clamp with a small amount of hose exposed at the end .

So, here's what I've found (and I'm not quite done yet, as I'm waiting on a couple of other parts to come in before I put everything back).

As you can see by this picture, the Tstat unit failed hard. The metal spring retainer is only held in place by about 1/16" of plastic on either side. The far right side has totally given way. Also note that the the smaller / top valve is now missing it's retention bulge - it was blown out when the hose disconnected.

Both the hose and the clamp look to be in very good shape, although I am replacing both. The clamp was still in the correct place on the hose (there's a painted indicator to show you where it belongs), but I have no way to tell where it was along the valve itself.

On to the learning. #1 is that the Twist II lock is a total pain in the ass to disconnect. There appears to be a tool you can use, but a helper with a screwdriver above along with me + screwdriver underneath got the job done. The ring doesn't have to be move more than about 3/4", but what a distance that is! When moved, you'll hear a barely audible click. Pic below for locked and unlocked.

Locked

Unlocked

#2 is that the larger hose has a wire lock that is pretty easy to open - just slide a pick under the top of it and pull up. No issues on that one, once you know what to do.

My daughter’s 2001 V70 kept blowing off the top radiator hose. The dealer did a pressure test on the cylinders and it turns out the cylinder was leaking through the head gasket into the coolant building up pressure and blowing the hose off.